Comparative Study on Mechanical Behaviour of Enzyme Modified Soils

Soil stabilization of soil has been carried out by many researchers in the past using conventional materials such as lime, fly ash, silica fumes, quarry dust etc. Ground improvement using enzymes or micro-organisms, fermented from vegetable extracts, has been one of the latest sustainable invents in Geotechnical Engineering. The present work explores and compares the effectiveness of Terrazyme in improving the mechanical properties such as strength and compressibility characteristics of locally available soils. The experimental studies are extended to two soils which possess extreme characteristics namely lateritic and black cotton soils. The work is carried out on 3 different dosages of Terrazyme namely 150 ml/m3, 200 ml/m3 and 250 ml/m3 respectively, obtained through volumetric proportioning. In order to understand the long-term behaviour pattern of Terrazyme, studies are carried out on varying curing periods (7 and 28 days) and results are compared. The results highlight that Terrazyme modification is more effective in black cotton soil than lateritic soil. To evaluate the change in soil fabric brought about on account of enzyme application, scanning electron microscope (SEM) and energy dispersive X Ray analysis (EDAX) studies are performed on these soils. The design of flexible pavement with an enzyme modified subgrade revealed a more robust and sustainable infrastructure solution.